Question

Assume that x has a normal distribution with the specified mean and standard deviation. Find the indicated probability. (Round your answer to four decimal places.)

μ = 106; σ = 10

P(x ≥ 120) =

Assume that x has a normal distribution with the specified mean and standard deviation. Find the indicated probability. (Round your answer to four decimal places.)

μ = 110; σ = 13

P(x ≥ 90) =

Answer 1

Solution :

Given that ,

mean = = 106

standard deviation = =10

P(x ≥ 120) = 1 - p( x< 120)

=1- p P[(x - ) / < (120 - 106) /10 ]

=1- P(z < 1.4)

Using z table,

= 1 -0.9192

answer =0.0808

Solution :

Given that ,

mean = = 110

standard deviation = =13

P(x ≥ 90) = 1 - p( x< 90)

=1- p P[(x - ) / < (90 - 110) /13 ]

=1- P(z < -1.54)

Using z table,

= 1 -0.0618

answer =0.9382